/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */
package wx.xml.xalan.xpath.patterns;

import wx.xml.xalan.xml.dtm.DTM;
import wx.xml.xalan.xml.dtm.DTMFilter;
import wx.xml.xalan.xpath.Expression;
import wx.xml.xalan.xpath.ExpressionOwner;
import wx.xml.xalan.xpath.XPath;
import wx.xml.xalan.xpath.XPathContext;
import wx.xml.xalan.xpath.XPathVisitor;
import wx.xml.xalan.xpath.objects.XNumber;
import wx.xml.xalan.xpath.objects.XObject;

/**
 * This is the basic node test class for both match patterns and location path
 * steps.
 *
 * @xsl.usage advanced
 */
public class NodeTest extends Expression {
    /**
     * The namespace or local name for node tests with a wildcard.
     *
     * @see <a href="http://www.w3.org/TR/xpath#NT-NameTest">the XPath NameTest production.</a>
     */
    public static final String WILD = "*";
    /**
     * The URL to pass to the Node#supports method, to see if the
     * DOM has already been stripped of whitespace nodes.
     */
    public static final String SUPPORTS_PRE_STRIPPING =
        "http://xml.apache.org/xpath/features/whitespace-pre-stripping";
    /**
     * Special bitmap for match patterns starting with a function.
     * Make sure this does not conflict with {@link org.w3c.dom.traversal.NodeFilter}.
     */
    public static final int SHOW_BYFUNCTION = 0x00010000;
    /**
     * The match score if the pattern consists of just a NodeTest.
     *
     * @see <a href="http://www.w3.org/TR/xslt#conflict">XSLT Specification - 5.5 Conflict Resolution for Template Rules</a>
     */
    public static final XNumber SCORE_NODETEST =
        new XNumber(XPath.MATCH_SCORE_NODETEST);
    /**
     * The match score if the pattern pattern has the form NCName:*.
     *
     * @see <a href="http://www.w3.org/TR/xslt#conflict">XSLT Specification - 5.5 Conflict Resolution for Template Rules</a>
     */
    public static final XNumber SCORE_NSWILD =
        new XNumber(XPath.MATCH_SCORE_NSWILD);
    /**
     * The match score if the pattern has the form
     * of a QName optionally preceded by an @ character.
     *
     * @see <a href="http://www.w3.org/TR/xslt#conflict">XSLT Specification - 5.5 Conflict Resolution for Template Rules</a>
     */
    public static final XNumber SCORE_QNAME =
        new XNumber(XPath.MATCH_SCORE_QNAME);
    /**
     * The match score if the pattern consists of something
     * other than just a NodeTest or just a qname.
     *
     * @see <a href="http://www.w3.org/TR/xslt#conflict">XSLT Specification - 5.5 Conflict Resolution for Template Rules</a>
     */
    public static final XNumber SCORE_OTHER =
        new XNumber(XPath.MATCH_SCORE_OTHER);
    /**
     * The match score if no match is made.
     *
     * @see <a href="http://www.w3.org/TR/xslt#conflict">XSLT Specification - 5.5 Conflict Resolution for Template Rules</a>
     */
    public static final XNumber SCORE_NONE =
        new XNumber(XPath.MATCH_SCORE_NONE);
    static final long serialVersionUID = -5736721866747906182L;
    /**
     * This attribute determines which node types are accepted.
     *
     * @serial
     */
    protected int m_whatToShow;
    /**
     * The local name to be tested for.
     *
     * @serial
     */
    protected String m_name;
    /**
     * The namespace to be tested for, which may be null.
     *
     * @serial
     */
    String m_namespace;
    /**
     * Statically calculated score for this test.  One of
     * {@link #SCORE_NODETEST},
     * {@link #SCORE_NONE},
     * {@link #SCORE_NSWILD},
     * {@link #SCORE_QNAME}, or
     * {@link #SCORE_OTHER}.
     *
     * @serial
     */
    XNumber m_score;
    /**
     * True if this test has a null namespace and a local name of {@link #WILD}.
     *
     * @serial
     */
    private boolean m_isTotallyWild;

    /**
     * Construct an NodeTest that tests for namespaces and node names.
     *
     * @param whatToShow Bit set defined mainly by {@link org.w3c.dom.traversal.NodeFilter}.
     * @param namespace  The namespace to be tested.
     * @param name       The local name to be tested.
     */
    public NodeTest(int whatToShow, String namespace, String name) {
        initNodeTest(whatToShow, namespace, name);
    }

    /**
     * Construct an NodeTest that doesn't test for node names.
     *
     * @param whatToShow Bit set defined mainly by {@link org.w3c.dom.traversal.NodeFilter}.
     */
    public NodeTest(int whatToShow) {
        initNodeTest(whatToShow);
    }

    /**
     * Null argument constructor.
     */
    public NodeTest() {
    }

    /**
     * Tell what node type to test, if not DTMFilter.SHOW_ALL.
     *
     * @param whatToShow Bit set defined mainly by
     *                   {@link wx.xml.xalan.xml.dtm.DTMFilter}.
     * @return the node type for the whatToShow.  Since whatToShow can specify
     * multiple types, it will return the first bit tested that is on,
     * so the caller of this function should take care that this is
     * the function they really want to call.  If none of the known bits
     * are set, this function will return zero.
     */
    public static int getNodeTypeTest(int whatToShow) {
        // %REVIEW% Is there a better way?
        if (0 != (whatToShow & DTMFilter.SHOW_ELEMENT))
            return DTM.ELEMENT_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_ATTRIBUTE))
            return DTM.ATTRIBUTE_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_TEXT))
            return DTM.TEXT_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT))
            return DTM.DOCUMENT_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT_FRAGMENT))
            return DTM.DOCUMENT_FRAGMENT_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_NAMESPACE))
            return DTM.NAMESPACE_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_COMMENT))
            return DTM.COMMENT_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_PROCESSING_INSTRUCTION))
            return DTM.PROCESSING_INSTRUCTION_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT_TYPE))
            return DTM.DOCUMENT_TYPE_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_ENTITY))
            return DTM.ENTITY_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_ENTITY_REFERENCE))
            return DTM.ENTITY_REFERENCE_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_NOTATION))
            return DTM.NOTATION_NODE;

        if (0 != (whatToShow & DTMFilter.SHOW_CDATA_SECTION))
            return DTM.CDATA_SECTION_NODE;


        return 0;
    }

    /**
     * Do a diagnostics dump of a whatToShow bit set.
     *
     * @param whatToShow Bit set defined mainly by
     *                   {@link wx.xml.xalan.xml.dtm.DTMFilter}.
     */
    public static void debugWhatToShow(int whatToShow) {

        java.util.Vector v = new java.util.Vector();

        if (0 != (whatToShow & DTMFilter.SHOW_ATTRIBUTE))
            v.addElement("SHOW_ATTRIBUTE");

        if (0 != (whatToShow & DTMFilter.SHOW_NAMESPACE))
            v.addElement("SHOW_NAMESPACE");

        if (0 != (whatToShow & DTMFilter.SHOW_CDATA_SECTION))
            v.addElement("SHOW_CDATA_SECTION");

        if (0 != (whatToShow & DTMFilter.SHOW_COMMENT))
            v.addElement("SHOW_COMMENT");

        if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT))
            v.addElement("SHOW_DOCUMENT");

        if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT_FRAGMENT))
            v.addElement("SHOW_DOCUMENT_FRAGMENT");

        if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT_TYPE))
            v.addElement("SHOW_DOCUMENT_TYPE");

        if (0 != (whatToShow & DTMFilter.SHOW_ELEMENT))
            v.addElement("SHOW_ELEMENT");

        if (0 != (whatToShow & DTMFilter.SHOW_ENTITY))
            v.addElement("SHOW_ENTITY");

        if (0 != (whatToShow & DTMFilter.SHOW_ENTITY_REFERENCE))
            v.addElement("SHOW_ENTITY_REFERENCE");

        if (0 != (whatToShow & DTMFilter.SHOW_NOTATION))
            v.addElement("SHOW_NOTATION");

        if (0 != (whatToShow & DTMFilter.SHOW_PROCESSING_INSTRUCTION))
            v.addElement("SHOW_PROCESSING_INSTRUCTION");

        if (0 != (whatToShow & DTMFilter.SHOW_TEXT))
            v.addElement("SHOW_TEXT");

        int n = v.size();

        for (int i = 0; i < n; i++) {
            if (i > 0)
                System.out.print(" | ");

            System.out.print(v.elementAt(i));
        }

        if (0 == n)
            System.out.print("empty whatToShow: " + whatToShow);

        System.out.println();
    }

    /**
     * Two names are equal if they and either both are null or
     * the name t is wild and the name p is non-null, or the two
     * strings are equal.
     *
     * @param p part string from the node.
     * @param t target string, which may be {@link #WILD}.
     * @return true if the strings match according to the rules of this method.
     */
    private static final boolean subPartMatch(String p, String t) {

        // boolean b = (p == t) || ((null != p) && ((t == WILD) || p.equals(t)));
        // System.out.println("subPartMatch - p: "+p+", t: "+t+", result: "+b);
        return (p == t) || ((null != p) && ((t == WILD) || p.equals(t)));
    }

    /**
     * This is temporary to patch over Xerces issue with representing DOM
     * namespaces as "".
     *
     * @param p part string from the node, which may represent the null namespace
     *          as null or as "".
     * @param t target string, which may be {@link #WILD}.
     * @return true if the strings match according to the rules of this method.
     */
    private static final boolean subPartMatchNS(String p, String t) {

        return (p == t)
            || ((null != p)
            && ((p.length() > 0)
                ? ((t == WILD) || p.equals(t)) : null == t));
    }

    /**
     * This attribute determines which node types are accepted.
     * These constants are defined in the {@link org.w3c.dom.traversal.NodeFilter}
     * interface.
     *
     * @return bitset mainly defined in {@link org.w3c.dom.traversal.NodeFilter}.
     */
    public int getWhatToShow() {
        return m_whatToShow;
    }

    /**
     * This attribute determines which node types are accepted.
     * These constants are defined in the {@link org.w3c.dom.traversal.NodeFilter}
     * interface.
     *
     * @param what bitset mainly defined in {@link org.w3c.dom.traversal.NodeFilter}.
     */
    public void setWhatToShow(int what) {
        m_whatToShow = what;
    }

    /**
     * Return the namespace to be tested.
     *
     * @return The namespace to be tested for, or {@link #WILD}, or null.
     */
    public String getNamespace() {
        return m_namespace;
    }

    /**
     * Set the namespace to be tested.
     *
     * @param ns The namespace to be tested for, or {@link #WILD}, or null.
     */
    public void setNamespace(String ns) {
        m_namespace = ns;
    }

    /**
     * Return the local name to be tested.
     *
     * @return the local name to be tested, or {@link #WILD}, or an empty string.
     */
    public String getLocalName() {
        return (null == m_name) ? "" : m_name;
    }

    /**
     * Set the local name to be tested.
     *
     * @param name the local name to be tested, or {@link #WILD}, or an empty string.
     */
    public void setLocalName(String name) {
        m_name = name;
    }

    /**
     * @see Expression#deepEquals(Expression)
     */
    public boolean deepEquals(Expression expr) {
        if (!isSameClass(expr))
            return false;

        NodeTest nt = (NodeTest) expr;

        if (null != nt.m_name) {
            if (null == m_name)
                return false;
            else if (!nt.m_name.equals(m_name))
                return false;
        } else if (null != m_name)
            return false;

        if (null != nt.m_namespace) {
            if (null == m_namespace)
                return false;
            else if (!nt.m_namespace.equals(m_namespace))
                return false;
        } else if (null != m_namespace)
            return false;

        if (m_whatToShow != nt.m_whatToShow)
            return false;

        if (m_isTotallyWild != nt.m_isTotallyWild)
            return false;

        return true;
    }

    /**
     * Initialize this node test by setting the whatToShow property, and
     * calculating the score that this test will return if a test succeeds.
     *
     * @param whatToShow Bit set defined mainly by {@link org.w3c.dom.traversal.NodeFilter}.
     */
    public void initNodeTest(int whatToShow) {

        m_whatToShow = whatToShow;

        calcScore();
    }

    /**
     * Initialize this node test by setting the whatToShow property and the
     * namespace and local name, and
     * calculating the score that this test will return if a test succeeds.
     *
     * @param whatToShow Bit set defined mainly by {@link org.w3c.dom.traversal.NodeFilter}.
     * @param namespace  The namespace to be tested.
     * @param name       The local name to be tested.
     */
    public void initNodeTest(int whatToShow, String namespace, String name) {

        m_whatToShow = whatToShow;
        m_namespace = namespace;
        m_name = name;

        calcScore();
    }

    /**
     * Get the static score for this node test.
     *
     * @return Should be one of the SCORE_XXX constants.
     */
    public XNumber getStaticScore() {
        return m_score;
    }

    /**
     * Set the static score for this node test.
     *
     * @param score Should be one of the SCORE_XXX constants.
     */
    public void setStaticScore(XNumber score) {
        m_score = score;
    }

    /**
     * Static calc of match score.
     */
    protected void calcScore() {

        if ((m_namespace == null) && (m_name == null))
            m_score = SCORE_NODETEST;
        else if (((m_namespace == WILD) || (m_namespace == null))
            && (m_name == WILD))
            m_score = SCORE_NODETEST;
        else if ((m_namespace != WILD) && (m_name == WILD))
            m_score = SCORE_NSWILD;
        else
            m_score = SCORE_QNAME;

        m_isTotallyWild = (m_namespace == null && m_name == WILD);
    }

    /**
     * Get the score that this test will return if a test succeeds.
     *
     * @return the score that this test will return if a test succeeds.
     */
    public double getDefaultScore() {
        return m_score.num();
    }

    /**
     * Tell what the test score is for the given node.
     *
     * @param xctxt   XPath runtime context.
     * @param context The node being tested.
     * @return {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_NODETEST},
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_NONE},
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_NSWILD},
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_QNAME}, or
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_OTHER}.
     * @throws javax.xml.transform.TransformerException
     */
    public XObject execute(XPathContext xctxt, int context)
        throws javax.xml.transform.TransformerException {

        DTM   dtm      = xctxt.getDTM(context);
        short nodeType = dtm.getNodeType(context);

        if (m_whatToShow == DTMFilter.SHOW_ALL)
            return m_score;

        int nodeBit = (m_whatToShow & (0x00000001 << (nodeType - 1)));

        switch (nodeBit) {
            case DTMFilter.SHOW_DOCUMENT_FRAGMENT:
            case DTMFilter.SHOW_DOCUMENT:
                return SCORE_OTHER;
            case DTMFilter.SHOW_COMMENT:
                return m_score;
            case DTMFilter.SHOW_CDATA_SECTION:
            case DTMFilter.SHOW_TEXT:

                // was:
                // return (!xctxt.getDOMHelper().shouldStripSourceNode(context))
                //       ? m_score : SCORE_NONE;
                return m_score;
            case DTMFilter.SHOW_PROCESSING_INSTRUCTION:
                return subPartMatch(dtm.getNodeName(context), m_name)
                       ? m_score : SCORE_NONE;

            // From the draft: "Two expanded names are equal if they
            // have the same local part, and either both have no URI or
            // both have the same URI."
            // "A node test * is true for any node of the principal node type.
            // For example, child::* will select all element children of the
            // context node, and attribute::* will select all attributes of
            // the context node."
            // "A node test can have the form NCName:*. In this case, the prefix
            // is expanded in the same way as with a QName using the context
            // namespace declarations. The node test will be true for any node
            // of the principal type whose expanded name has the URI to which
            // the prefix expands, regardless of the local part of the name."
            case DTMFilter.SHOW_NAMESPACE: {
                String ns = dtm.getLocalName(context);

                return (subPartMatch(ns, m_name)) ? m_score : SCORE_NONE;
            }
            case DTMFilter.SHOW_ATTRIBUTE:
            case DTMFilter.SHOW_ELEMENT: {
                return
                    (m_isTotallyWild || (subPartMatchNS(dtm.getNamespaceURI(context), m_namespace) && subPartMatch(dtm.getLocalName(context), m_name)))
                    ? m_score : SCORE_NONE;
            }
            default:
                return SCORE_NONE;
        }  // end switch(testType)
    }

    /**
     * Tell what the test score is for the given node.
     *
     * @param xctxt   XPath runtime context.
     * @param context The node being tested.
     * @return {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_NODETEST},
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_NONE},
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_NSWILD},
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_QNAME}, or
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_OTHER}.
     * @throws javax.xml.transform.TransformerException
     */
    public XObject execute(XPathContext xctxt, int context,
                           DTM dtm, int expType)
        throws javax.xml.transform.TransformerException {

        if (m_whatToShow == DTMFilter.SHOW_ALL)
            return m_score;

        int nodeBit = (m_whatToShow & (0x00000001
            << ((dtm.getNodeType(context)) - 1)));

        switch (nodeBit) {
            case DTMFilter.SHOW_DOCUMENT_FRAGMENT:
            case DTMFilter.SHOW_DOCUMENT:
                return SCORE_OTHER;
            case DTMFilter.SHOW_COMMENT:
                return m_score;
            case DTMFilter.SHOW_CDATA_SECTION:
            case DTMFilter.SHOW_TEXT:

                // was:
                // return (!xctxt.getDOMHelper().shouldStripSourceNode(context))
                //       ? m_score : SCORE_NONE;
                return m_score;
            case DTMFilter.SHOW_PROCESSING_INSTRUCTION:
                return subPartMatch(dtm.getNodeName(context), m_name)
                       ? m_score : SCORE_NONE;

            // From the draft: "Two expanded names are equal if they
            // have the same local part, and either both have no URI or
            // both have the same URI."
            // "A node test * is true for any node of the principal node type.
            // For example, child::* will select all element children of the
            // context node, and attribute::* will select all attributes of
            // the context node."
            // "A node test can have the form NCName:*. In this case, the prefix
            // is expanded in the same way as with a QName using the context
            // namespace declarations. The node test will be true for any node
            // of the principal type whose expanded name has the URI to which
            // the prefix expands, regardless of the local part of the name."
            case DTMFilter.SHOW_NAMESPACE: {
                String ns = dtm.getLocalName(context);

                return (subPartMatch(ns, m_name)) ? m_score : SCORE_NONE;
            }
            case DTMFilter.SHOW_ATTRIBUTE:
            case DTMFilter.SHOW_ELEMENT: {
                return
                    (m_isTotallyWild || (subPartMatchNS(dtm.getNamespaceURI(context), m_namespace) && subPartMatch(dtm.getLocalName(context), m_name)))
                    ? m_score : SCORE_NONE;
            }
            default:
                return SCORE_NONE;
        }  // end switch(testType)
    }

    /**
     * Test the current node to see if it matches the given node test.
     *
     * @param xctxt XPath runtime context.
     * @return {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_NODETEST},
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_NONE},
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_NSWILD},
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_QNAME}, or
     * {@link wx.xml.xalan.xpath.patterns.NodeTest#SCORE_OTHER}.
     * @throws javax.xml.transform.TransformerException
     */
    public XObject execute(XPathContext xctxt)
        throws javax.xml.transform.TransformerException {
        return execute(xctxt, xctxt.getCurrentNode());
    }

    /**
     * Node tests by themselves do not need to fix up variables.
     */
    public void fixupVariables(java.util.Vector vars, int globalsSize) {
        // no-op
    }

    /**
     * @see wx.xml.xalan.xpath.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
     */
    public void callVisitors(ExpressionOwner owner, XPathVisitor visitor) {
        assertion(false, "callVisitors should not be called for this object!!!");
    }

}
